The present invention relates to the automatic cutting of pieces from a layup of sheet material and deals more particularly with a method and apparatus for bundling stacks of cut pieces together with fasteners and for thereafter removing the bundled stacks from the adjacent waste material.
When mass producing garments, upholstery and similar items, it is known to cut pattern pieces from layups of cloth or other flexible sheet material formed by spreading multiple plies of such sheet material on top of one another. A single traversal by a cutting knife of a cutting path having a shape corresponding to the periphery of a pattern piece therefore cuts an entire stack of pattern pieces having the same size and shape. Differently shaped pattern pieces are generally laid out in an optimal fashion over the surface of the layup to maximize usage of the layup material and to leave as little waste material as possible. The cutting knife is often guided around the cutting path by a numerical controller in which the outlines and peripheries of the pattern pieces are defined by data stored on a computer tape or other storage medium.
Many different kinds of cutting tables are known. Since the cutting of the pattern pieces is relatively fast when compared to the spreading of the layup, the layup is usually not spread directly over the cutting table. Instead, the surface on which the pieces are cut may be elongated to provide a separate spreading surface on which the layup can be first spread and then slid onto the cutting surface. The layups are usually spread over an easily slideable sheet material to facilitate later sliding of the layup from surface to surface. After the layups have been cut, they may be slid off the cutting surface and onto a take-off surface or table where the stacks of cut pattern pieces will be removed.
Alternatively, some cutting tables are moveable between several spreading tables on which layups may be simultaneously spread. The cutting table is moved adjacent to a spreading table on which a layup has been spread, the layup is transferred to the cutting table and the layup is then cut. The cut layup is then transferred to a take-off table and the cutting table is moved to the next spreading table with a completed layup. The cutting table can also be moveable relative to several take-off tables, so that after the layup has been cut, the cutting table is moved adjacent to an empty take-off table and the cut layup transferred thereto.
Once stacks of pattern pieces have been cut from a layup, it is customary to individually bundle them to facilitate their future handling and storage. This bundling can be done by manually removing the stacks of pieces and tying them with string or wrapping them with adhesive tape. The stacks can also be automatically bundled while still on the cutting table or similar support by projecting staples or thread stitches through the stacks as disclosed in U.S. Pat. No. 3,765,349 issued on Oct. 16, 1973 to the present assignee.
The degree of automation achieved with known cutting tables makes it desirable to automate the removal process whether the bundled stacks of pattern pieces are removed from the layup on the cutting table or at a later take-off table. Since the exact shapes, sizes and locations of the bundled stacks have already been determined by the cutting tool controller, it is desirable to remove the stacks of pieces with an automatic take-off device or robot that acts in-concert with the cutting tool controller.
In addition, since many different stacks of pattern pieces can be cut from one layup, it is easy to confuse similarly shaped pieces once they are removed from the table. The stacks of pieces are therefore customarily labelled with identifying information to prevent such confusion. Labelling of the stacks of pieces has previously been separate from the bundling step. It is thus desirable to provide a method and apparatus which combine the labelling and bundling steps to reduce the time required and to simplify the apparatus involved.
Accordingly, it is an object of the present invention to provide a method and apparatus by which the cutting tool control means can work in concert with an automatic take-off device to facilitate removal of the stacks of pieces after a cutting operation.
It is a further object of the present invention to provide a method and apparatus which combines the bundling and labelling of cut stacks of pieces.
It is still another object of the present invention to provide a method and apparatus by which the bundling and labelling of cut stacks of pieces is performed in response to data provided by the cutting tool control means.